Bomb fuze



R. o. WYNN 2,748,709

BOMB FUZE 4 Sheets-Sheet l June 5, 1956 Filed sept. 1:5, 194e R. O. WYNN ID rf) R. O. WYNN BOMB FUZE June 5, 1956 gwua/wbofo R. O. WYNN abbot/w1 4 Sheets-Sheet 2 June 5, 1956 R. o. `WYNN 2,748,709

BBBBBB ZE go amno BoMB ruzie 'risticii o. Wynn, Hairston, Tex.

Application September 13, 1946,y Serial N; 696,969 8 Cliiiins. (ci. to2-'312) (Granted under Tine se, U. s. ceac (i952), sce. 26e) This invention relates to a fuze for detonating anexplosive charge and rnore particularlysto a bomb fune in which the tiring thereof is accomplished substantially instantaneously upon impact of the bomb with the' target.y

011e of' the objects of the present invention is to provide a fuze for a bomb having new and improved arming means arranged therein and adapted to be moved. to an armed position during the free flight ofv the bomb toward the target.

Another object is to provide a new and improved fuzel for a` bomb having a pair of ring pins adapted to be re*- tracted from an initial safe position to a tiring position as the` bomb moves toward the target and to lire the explosive charge within the bomb upon impact of the bomb withthe target.

Another object is to provide a new and. improved fuzefor a bomb having improved armiilgineansarranged therein adapted to be held in an initial safe position by dual iirillg means until the bomb is dropped from an air craft in flight whereby the arming thereof doesV notV take plac'e except during the free flight of the bomb toward the target.-

Afurther object is toprovide a new and improved f fora bomb in which the dual tiring pins are moved frf an initial safe position to a tiring po'sitiorn and including an arming member having dual detonatingl means ar"- ranged therein, the arming member being adaptedl to be moved from an initial safeV position toy an armed position after. the arming member has been released by the tiring pins, during the free flight of the bomb toward the target.

Another object is to provide a new and improved hize feia bomb in which uic percussion caps arc moved frein im initial safe position to an armed position therebyto establish an explosive train between the percussion caps aiidabooster charge and in which the percussionV capsre adapted tozbe tired by frangible firing pins upon impact of thefuze with the target thereby to' explode the" booster' charge.

Another object is to provide a new and improved fuze for a-bomb having dual explosive trains and dual percussion capsarranged therein adapted to be tiredV by dual frangible firing pins upon impact of the bomb with the target whereby the bomb is invariably iire'd as the' bomb strikes the" target.

A still further object is to provide a new and;v impvd fu'ze `forr'a bomb which is economical to manufacture, re-l liable; in operai-ion and which possesses all the qualities' ofruggedness and dependability in service.4

stillv einer chiens, advantages and iiiiprcvcineins will be apparent from the following description taken in coiii iiccf-icn with flic accompanying sri'vwiiigs,` or` which:

rig..V l is a ccmrsl longitudinal scci-iciial view of" sie size :indi a` portion of the bom-b' to'v/hicfh the fu'ze issciiredj Fig.; 2A is a similar viewcr Fig. l' biifshowing' itie fnze inaniarmed condition;

Fig. 3v is enlarged scenarist view faken sii line 31:3 Qf Fig:

2,748,7@9 Patented June 5, 1956 ice Fig'. 4; is an enlarged sectional view taken en line 4 4 f Fig. 2;

Fig. 5 is an enlarged sectional view taken on line 5 5 flfis.. 23 Y Fig. a fragmentary sectional view taken on line 646 of Fig. 4; l M

Fig. 7 is' 'a top' plan view of the arming member employe'd inthe fliz'e; n v v Fig. s is sii elevational vic'w of flic aiming member cf Fig;

Figi, 9 is a bottom view ofthe arming member of Fig. 7i and' Fig. 10 is an elevstieiial view similar tc Fig. 's but at a rig-'lit angle inercia. Y l

Referring how to the drawings Afor a more complete iljiids'tandiii'g of the invention and more particularlyrto Fig. A1I thereof oil which is shown a fragmentary portion f bdmb` indieated generally by the numeral 10 and comprising. a'. casing 11 having arranged therein the usual iipls'ive charge 12 as is Well known to those skilled in the art t which the invention pertains. v It will be understood, however, that the bomb is re'' leasably supported by an aircraft in ilight in any suitable in'r, and an arming wire connected to the aircraft in the illslilV manner is preferably employed to prevent r'otativermvement of the propeller 14 associated with the fiie 15 of the present invention; The fuze 15 comprises ah adapter 16 secured tothe nose of the bomb in any hieni'r'lt manner as by threading the parts together and indicated by lthe reference character 17. A- shoulder 18 is preferably formed on the bomb, Figs. l and 2; and adapted to have vabutting relation with respect to an en-A larged; heady 19 formed on the adapter 16 therebyv to at tell the fuze more securely to the bomb. The enlarged hd 19 of the adapter 15 is provided with a plurality of recesses Zliwhevreby a Spanner Wrench or the like may be employed for threading the adapter 16 into the nose of the bomb, Figs.v 1 and 2.

A tiring pin carriage support generally indicated by the reference character 22 is slidably arranged within the adapter` 16 and comprises an annular member 23 having a reduced. nipple 274 formed thereon adapted to exteiidr predetermined distance into a bore 25 formed th adapter 16 thereby to provide a supporting guide for the ringhpincarriage support during sliding movement thereot.; integrally formed on the annular member 23 f the tiring pin carriage support is a relatively thin harige 26 hav'- ing a plurality of apertures 27 therein, the purpose of which will be more clearly apparent as the des'c'riptiol'i proceeds. Supported by the adapter 16 in any suitable manner, butV preferably by threading thepart's together as at 25, is av housing or tubular member generally indicated by the reference character 29. The housing 29 extends a prede; termined distance into the explosive charge 12 and is adapted to be secured to the v 'adapter by screws or pins 31 thereby preventing rotation of the housing 29 with respect tothe adapter after assembly of these parts. The other end of the housing 29 has formed therein a recess 32 the walls thereof b'eing threaded as at 33; having engagement with a threaded portion of a container 34, the coil tainer 34 at one end thereofv beingc'lo's'ed as at 35 thereby to receiveV and.r support an explosive booster charge *36. Comunication with the recess 32 formed in the housing 29 is aboe 37, having rotatably arranged therein an rirling `xiiei'rber generallyindicatedl by the reference character 38.V A- disc member 39 is arranged within the housingl 29 between the lower surface of' the arming member 38 and the open end of the container 345 the disc being maintained in liked position Within the housing 29 by pin r sc"r"evv 41 arranged in the housingV and ir'teriding nit a slot 42 provided in the disc 39. The disc 39 is provided' with a` pair of spaced openings or bores 43 extending therethrough and adapted respectively to receive and support a pair of lead-in charges 44. understood, however, that the lead-in charges are adapted to fire the booster charge after the arming member 38 has been released and rotated to an armed position and upon impact of the bomb with the target.

` The tiring pin carriage 22 is provided With a pair of spaced bores 45 having a pair of pins or rods 46 preferably knurled as at 50 and respectively secured therein as by a press t, the pin-s being of such length as to extend a predetermined distance beyond the lower surface of the reduced nipple 24 substantially as shown on Figs. 1 and 2 of the drawings. Secured to the extending portion of each pin 46 respectively, Figs. 1 and 2, area pair of frangible tubes 47 composed of any suitable material such for example, as brass or aluminum. Each tube 47 is slideably arranged within a bore 48 disposed within the housing 29 and are of such length as to extend therethrough and into a recess 49 formed in the arming member 38 thereby maintaining the arming member in an initial safe position, Fig. 1, until the bomb is released from the aircraft whereupon arming thereof will not occur except during the free ight of the bomb toward the target. in any suitable manner such, for example, as by press fit knurl 60 are a pair of striker members 51, each having an anvil 52 formed thereon of suflicient diameter to abut the end of the tube, the purpose of which will more clearly appear as the description proceeds. understood, however, that the tubes 47 maintain the arming member 38 in an initial safe position thereby to prevent rotation and arming thereof until the bomb is released from the aircraft in ight and has traveled a predetermined distance therefrom.

Rotatably arranged within the support 22 is a sleeve 53 having one end thereof threaded as at 54 for threaded engagement with a bore 55 provided in the housing 29. The sleeve 53 is provided with a bore 56 axially arranged It will be' Secured in one end of each tube 47 respectively It will be therein, within which is rotatably disposed a shaft or rod l 57. The other end of the sleeve 53 is reduced as at 58 to form a shoulder 59 thereon adapted to have abutting relation with respect to a shoulder 61 formed on the carriage 22 and thus the sleeve is rotatably supported therein and the carriage 22 is also slidably supported in the bore 25 provided in the adapter 16. Arranged about the reduced portion 58 of the sleeve 53 is a spacer 62, the spacer being disposed between the outer surface of the support 22 and a gear 63, the gear being supported by the sleeve 53 and rotatable therewith, the sleeve having one end thereof upset as at 64 thereby maintaining the gear in fixed position on the reduced portion 58 of the sleeve.

The shaft 57 extends through the bore 56 in the sleeve Y53 and a collar 65 is formed thereon, the collar being adapted to have abutting relation with respect to one end of the sleeve 53, the other end thereof having secured thereto in any convenient manner a hub 66 as by a washer 67 and screw 68, Figs. 1 and 2. Secured to the shaft 57 in any suitable manner is a gear 69 adapted to impart rotative movement to the shaft 57 thereby rotating the arming member to an armed position after the arming member has been released by the tubes 47.

I Secured to the hub 66, in any convenient manner but preferably by a pair of spaced studs 71 and 72 is a shield or guard 73, the studs 71 and 72 being adapted to extend a predetermined distance beyond the guard 73, Figs. 1 and 2. Rotatably supported on the bearing portion 74 of the stud 71 and in continuous mesh with the gears 63 and 69 is an idle or driving gear 75 and rotatably supported on the bearing portion 76 of the stud 72 is a counterbalance weight 77, the gear 69 having one tooth less than the gear 63. From the foregoing, it will be apparent that a structure has been disclosed in which the sleeve 53 is adapted to rotate at a greatly reduced rate of vouter end of the nipple.

4. of the planetary gear arrangement disclosed. A washer 78 is arranged about the shaft 57 and disposed between the gear 69 and the inner surface of the shield 73.

A bearing sleeve 79 is arranged within a flange nipple 81 and is adapted to receive and be supported on the hub 66, the nipple being secured to the propeller 14 as by pins 82 Figs. 1 and 2. The pins 82 are provided with enlarged heads 83 adapted to engage complementary recessed portions 84 provided within the hub 66, and to impart rotative movement thereto as the result of the pressure of the air against the propeller 14 during the free flight of the bomb toward a target. The propeller is secured to the hub 66 in any suitable manner such, for example, as by the snap ring 85 arranged within the nipple 81 and maintained therein by a flange 86 formed on the The snap ring 85 is adapted to engage a groove 87 provided in the hub 66 thereby detachably securing the propeller to the hub. Furthermore, by employing a snap ring for securing the nipple 81 to the hub 66, the propeller 14 may be attached to the fuze quickly and easily at the time the bomb is releasably secured to the aircraft.

The hub 66 is restrained from rotation during transportation of the bomb by the aircraft by the aforesaid arming wire 13 which is normally arranged within one of a plurality of apertures 27 in the carriage 22 and one of a plurality of complementary apertures 89 arranged within the guard 73. Secured to the nipple 81 in any suitable manner such, for example, as by a press t is a protector cap 91.

A pair of diametrically disposed stop pins 92 are threaded into openings 93 in the adapter 16, as best shown on Fig. 5, the pins being adapted to extend into recesses 94 respectively arranged within the slideable carriage 22 thereby to limit the outward movement of the carriage within the adapter as the carriage is moved outwardly by the threaded sleeve 53 during the free ight of the bomb toward the target.

v The arming member 38 is provided with a pair of diametrically disposed bores 95 extending therethrough, each bore having a cartridge 96 arranged therein, the cartridge within each bore comprises a percussion cap 97, percussion pin 98, tetryl lead 99 and a sensitive primer 101. It will be understood, however, when the fuze is in the armed position shown on Fig. 2 of the drawings the cartridges 96 are in line with the lead-in charges 44 and also in line with the anvils 52, the tubes supporting the anvils having been moved outwardly a predetermined amount during the free ight of the bomb toward the target thereby releasing the arming member 38 and permitting the arming member to be rotated to the armed position by the shaft 57 before the bomb strikes the target. Thus upon impact of the bomb with the target the anvils 52 supported by the frangible tubes 47 will strike the percussion pins 98 with suflicient force to re the percussion caps 97 thus initiating firing of the booster charge 36 thereby to cause explosion of the bomb.

From the foregoing description it will be understood that upon impact of the bomb with the target, the frangible tubes 47 supporting the anvils 52 will buckle after the tubes have been driven rearwardly by the force of impact of the bomb with the target and both of the anvils supported within the tubes strike the percussion pins with suicient force to initiate ring thereof. Thus the buckling of the tubes prevents damage to the arming member and explosive train arranged therein until the bomb is tired thereby assuring proper functioning of the bomb as the bomb strikes the target.

The arming member 38 is also provided with a pair of spaced pins 102, Fig. 6, adapted to extend into spaced recesses 103 arranged in the housing 29 thereby to lock the arming member 38 in an armed position. The pins 102 are adapted to have sliding movement in spaced bores 104 provided in the arming member 38, the bores 104 being in registration with enlarged bores 105 adapted vto slideably receive the enlarged; heads 106' respectively formed on .eaohr pin 102. The pins are. urged into the recesses 103 by springs 107, thereby` to lock tlie arming member 38in an armed position, Fig. 6, when the arming memberl has been rotated a predetermined amount by the shaft 57 during the free flight of the". bomb toward the target It will be understood, however, that the arming member is maintained in an initial safe position by the tubesV 47 and rotativemoveme'nt thereof is prevented until the tubes 47 are withdrawn from the recesses 49; When thisoccurs rotative movement is imparted to the arming member 38 by the shaft 57,l the shaft. having a attened: or restricted portion 108 formed thereon adapted to extend through an elongated axial borey 109'wliich communicates with a; restricted bore 110 provided inthe arming member 38,- the shaft 57 being of su'chlength as to continually engage the bores 1.09 and 110 inthel arming member so that rotative movement will be transmitted thereto by the shaft through. the planetary gearing when the tubes 4'.7 have beenmoved out of the'recesses 49'of the arming member whereupon rotative movement is imparted to the arming member by the shaft 5:7'and thus the arming member is rotated to an armed position, Figs; 2 and 3.

During rotation of the sleeve 53 it will, be understood that the portion 108 of the shaft 57` willfslide through the bore 109, but when the sleeve has been rotated a predetermined amount further rotation thereof and sliding movement of the carriage 22 is prevented as'the stop pins 92 engage the rear walls of the slots 94 as shown in dashed outline on FigA 2.. When this occurs the tubes 47 are disengaged from the recesses 49 inthe arming member 38, the arming member is free to be rotated to' an armed position by the'shaft 57 as the restricted por tion 108 on the shaft engages. the restricted bore' I-10 in the arming member. It will be` understood, however, that rotative movement is imparted to the shaft 57 through gears 69 and 75 of the planetary gearing at the time when gear 63v is stationary. However it will be further understood that rotation of the arming. member to the armed vposition will not occur until the tubes 47 have been. moved to a released or firing positionV by theA sliding movement imparted thereto as the carriage is moved outwardly by the rotating sleeve 5-3. The operation of the device will be best understood by consideration of a specic example.

LetV it be assumed, for the purpose of description, that the bomb is released from an aircraft. in flight; As the bomb falls, away from the aircraftthearming wirev 13 is withdrawn by the static line, thereby releasing the propel# ler 14 for rotation. When the propeller` 14 has made a predetermined number of revolutions during the free tiight of the bomb through the air, the fuze. is arned as shown on Figs. 2 and 4 ofthe drawings.- During the arming. of the fuze, the sleeve 53v will make a sufficient number ofrevolutions within the casingy so that; the car-A riage secured thereto will slidea predetermined distance within the adapter, thereby to disengage the firing pins from. the arming member. Further movement of the carriage 22 is prevented by the stop pins 92 engaging the carriage whereupon the shaft 57 is rotated substantially a quarter turn thus rotating the arming member 38 to an" armed position due to the. driving connection between the shaft and the arming member as heretofore described, which driving connection` includes the portion108 on the shaft and the elongated bore 109 in the arming member.- It` will o'e understood, however, that Whenthe arming member has been moved to an armed positionV by the shaft S7, pins 102 lock the arming member in the. armed position, Fig. 6'. Impact of the anvils 52 against the percussionpins 98 causes the' bomb to explode` as the bomb strikes the target.

Briefiy stated. in summary, the present invention conf templates the provision of a new and improved fuze in which dual means are ernployed` for tiring thefuze when 6 thel bomb strikes the target, inwhich* the tiring pins are constructed in suc-h a manner as to buckle as the bomb strikes Vthe target thereby preventing damage tol the explosive cartridges and arming member 38 and. as'- suringr the invariable explosion of the bomb.

While the invention has been described with reference to a preferred example thereof which gives satisfactory results, it will be obvious to those skilled in the art to which the invention pertains, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is my intention, therefore, inthe appended claims to cover all such changes and modifications.

The invention herein described and claimed may be manufactured and usedV by or for the' Government of the United States of Americafor governmental purposes without payment of any royalties thereon or therefor. V

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A fuze for a bomb adapted to be fired by impact with a target, saidfuze comprising a casing supported by the bomb and extending a predetermined distance therein, an explosive charge arranged within said casing., a releasable arming member rotatably supported within the casting in an initial safe position and having a pair of diametrically disposed bores arranged therein, a pair of ringdevices slideably supported within said casing and disposed within said bores respectively for releasably locking the arming member in said initial safe position and adapted to release the arming member when the tiring deviceshave been moved a predetermined` amount suiicient to be disengaged from said bores, a. carriage slideably arranged within said casing andV supporting said ring devices for moving said tiring devices. said predeter mined amount, means includingl a sleeve rotatably supported within said carriage and in threaded engagement with said casing for imparting sliding movementto Said carriage as the sleeve rotates, complementary means on said arming member, a shaft rotatably supported within said sleeve in engagement with said complementary means for rotating the arming member yfrom the initial safe position to an armed position as the ring devices are disengaged from said bores, and means for locking said arming member in said armed position.

2. A fuze for a bomb adapted to be dropped on a target from an aircraft in. flight and comprising a casing supported by the bomb, an explosive charge arranged within said casing, a releasable arming member rotatably supported within said casing in an initial safe position' and having a pair of bores disposed therein, a carriage slideably arranged within said casing, a pair of frangible tiring devices securedto said carriage and extendinginto said bores respectively for locking said arming member in said initial safevposition and adapted to release the arming member when the carriage has been moved a predetermined amount sufficient to disengage saidfring devices from said bores, a shaft rotatably supported within said carriage, complementary means on saidl arming member, splined means on said shaft in engagement with said complementary means for rotating the arming member from said initial safe position to said armed position as the arming member is released by said ytiring devices, a sleeve supported within said casing and rotatably se cured to said carriage, complementary means on the casing, means on said sleeve inv engagement with said co plementary means onV the casing for imparting sliding movement to said carriage as the sleeve rotates thereby to disengage said firing devices from said bores, meansfin-` cluding a propeller for imparting rotative movement to said shaft and sleeve during thefree ight of theV bomb toward the target, and a pair of percussion detonators arranged within; said arming memberv and adapted` to' be tiredby said frangible iiring devices upon impact of the' bomb with the tar-get thereby to explode' said explosive charge. f

guapos 3. A fuze for a bomb adapted to be dropped on a target from an aircraft in flight and comprising a casing supported by the bomb, a booster charge arranged within said casing, a releasable arming member rotatably supported within the casing in an initial safe position and having a pair of diametrically arranged bores disposed therein, a carriage slideably supported within said casing, 'a pair of -frangible tiring devices respectively secured within said carriage and disposed within said bores for locking said arm-ing member in said initial safe position 'and adapted to release the arming member when the carriage has been moved sufficiently to disengage said firing devices from said bores, means including a sleeve rotatably threaded to said casing for moving the carriage sufficiently to disengage said firing devices from said bores as the sleeve rotates, a shaft rotatably support within said sleeve complementary means on said arming member, a splined portion on said shaft in engagement with said complementary means on the arming member for moving the arming member to an armed position when the sleeve has lmadea predetermined number of rotations and said firing devices are disengaged from said bores, means including a propeller on said shaft for imparting rotative movement thereto after the carriage has moved a predetermined distance thereby to release said arming member, complementary means on the casing, and means including a pair of spring actuated plungers arranged within the arming member and adapted to coact with said complementary means on the casing for locking the arming 'member in said armed position whereby said firing devices are adapted to fire said booster charge upon impact of the bomb with the target.

4. A fuze for a bomb adapted to be dropped on a target from an aircraft in flight and comprising an adapter secured to the bomb, a casing supported by said adapter and extending within said bomb, a container supported by said casing and having a booster charge arranged therein, a releasable arming member rotatably supported within said casing in an initial safe position and having a pair of diametrically disposed bores arranged therein, a carriage slideably arranged within said adapter, a pair of tiring devices secured to said carriage and disposed within said bores for releasably locking said arming member in said initial safe position and adapted to release the arming member when the carriage has been moved a predetermined amount, a sleeve rotatably threaded within said carriage for imparting sliding movement to the carriage as the sleeve rotates, a shaft rotatably supported within said sleeve, complementary means on said arming member, splined means on said shaft adapted to coact with said complementary means on said arming member for rotating said arming member to an armed position when the carriage has been moved said predetermined amount by the sleeve thereby to release said tiring devices from said bores, means including a propeller on said shaft for imparting rotative movement to said shaft, and a pair 'of plungers arranged within the arming member for maintaining the arming member in said armed position whereby said firing devices are adapted to fire said booster charge upon impact of the bomb with the target.

5. A fuze for a bomb adapted to be dropped on a target from an aircraft in flight and comprising a casing supported by the bomb, a booster charge arranged within said casing, a releasable arming member rotatably supported within said casing in an initial safe position and adapted to be moved to an armed position, a pair of lead-in charges arranged within said casing in operative relation with respect to said booster charge, a slideable carriage arranged within said casing, a pair of frangible tubes secured within said carriage, said tubes having a pair of firing anvils respectively secured thereto, said tubes being adapted to releasably lock said arming member when the arming member is insaid initial safe position and adapted to releasethe arming member when the carriage has moved a predetermined distance, a sleeve lli rotatably threaded within said carriage for moving the carriage said predetermined distance thereby to release said arming member during the free ight of the bomb toward the target, means secured to said casing for preventing further sliding movement of the carriage when the sleeve has made a predetermined number of revolutions corresponding to said predetermined distance, a shaft rotatably supported within said sleeve, means on said shaft for rotating the arming member from said initial safe position to said armed position when the Carriage has moved said predetermined distance and said sleeve has been rotated said predetermined number of revolutions, a pair of spring actuated plungers arranged within said arming member for locking the arming member in said armed position, and a pair of detonating devices arranged in the arming member and adapted to be moved into registered relation with said lead-in charges and said anvils respectively when the arming member moves to the armed position, said pair of frangible tubes being adapted to buckle when the anvils strike and fire said detonating devices upon impact of the bomb with said target.

6. A fuze for a bomb adapted to be dropped on a target from an aircraft and comprising a casing supported by the bomb, a releasable arming member rotatably supported within the casing and constructed and arranged to be moved from an initial safe position to an armed position, said arming member having a pair of bores arranged therein, a slideable carriage arranged within said casing, a pair of frangible tubes secured to said carriage, a pair of firing anvils respectively secured within said tubes and disposed within said bores respectively for releasably locking the arming member in said initial safe position and adapted to release the arming member when said firing anvils are disengaged from said bores as the carriage is moved a predetermined amount, means rotatably supported within said carriage and threaded to the casing for moving the carriage said predetermined amount during the free flight of the bomb toward the target, means secured to the casing for preventing further movement of the carriage when said threaded means has made a predetermined number of revolutions corresponding to said predetermined amount, a shaft supported within said threaded means and movable therewith, propeller means on said shaft for imparting rotative movement to the shaft and to said rotatably supported and threaded means during said free flight a slotted portion on said arming member, and a splined portion on said shaft and extending into said slotted portion for rotating the arming member from said initial safe position to said armed position as the arming member is released.

7. A fuze for a bomb adapted to be dropped on a target from an aircraft in flight and comprising a casing secured to the bomb, a releasable arming member rotatably supported within said casing in an initial safe position and constructed and arranged to be moved toan armed position, a slideable carriage arranged within the casing, a pair of tubes secured to said carriage and movable therewith and extending respectively into a pair of bores arranged within said arming member for releasably locking the arming member in said initial safe position and unlocking the arming member for rotation to an' armed position when the carriage and tubes are moved a' predetermined amount, a sleeve rotatably threaded to said casing for moving the carriage and tubes said predetermined amount, a shaft rotatably supported within said sleeve and movable therewith, means including a propeller on said shaft for imparting rotative movement to said shaft and sleeve during the free flight of the bomb toward the target, a' slotted portion in said arming member, splined means on said shaft in engagement with said slotted portion for rotating the arming member from said initial 'position to said armed position as said arming member is released, a pair of detents on said casing, and a pair of spring actuated plungers arranged within the arming member and adapted to coact with said detents and lock the member in said armed position.

8. An arming device for a bomb fuze comprising a casing supported by the bomb, a releasable arming member rotatably supported Within the casing and constmcted and arranged to be moved from an initial safe position to an armed position, said arming member having a pair of bores arranged therein in spaced relation with respect to each other, a slideable carriage arranged within said casing, a pair of rods secured to said carriage in mutual spaced relation, a pair of frangible tubes respectively secured to said rods and adapted to buckle upon impact of the bomb with a target, a pair of ring anvils respectively secured to said tubes and disposed within said bores for locking said arming member in said initial safe position and adapted to release the arming member when said ring anvils are disengaged from said bores as the carriage is moved a predetermined amount, sleeve means rotatably supported Within and threaded to the casing for moving the carriage said predetermined amount, a shaft supported Within said sleeve and movable therewith, a slotted portion on said arming member, a splined portion on said shaft in engagement with said slotted portion for rotating the arming member to said armed position as the arming member is released, and means including a propeller secured to said shaft and operatively connected to said sleeve for imparting movement to said shaft and sleeve during the free ilight of the bomb toward a target.

References Cited in the le of this patent UNITED STATES PATENTS 2,400,100 Byrnes et al May 14, 1946 2,407,844 Moriarty Sept. 17, 1946 2,409,205 Graumann Oct. 15, 1946 2,420,237 Girouard May 6, 1947 

